Live longer, get stronger, and keep your brain performing optimally—these are just a few of the many reasons to take vitamin D. Vitamin D is so important that it is on our Foundation Five list of the top five supplements that everyone should take. Despite the importance of vitamin D, confusion remains about how much you need and why. This article will cover the health reasons to take vitamin D and provide guidelines for testing and supplementation.
The Wonderful Vitamin D
Vitamin D is essential for life. Your body knows this, synthesizing vitamin D in the skin in response to sun exposure. Vitamin D can also be gotten from the diet or taken in supplement form. Researchers find that many people are chronically deficient in vitamin D because they don’t get regular full body exposure to the sun. Additionally, it is difficult to get adequate amounts from the diet even if you regularly eat foods that contain vitamin D, such as fish or fortified milk. Supplementing with vitamin D tablets or fish oil, specifically cod liver oil, is a great way to get vitamin D.
Who Is At Risk of Vitamin D Deficiency?
Levels of vitamin D deficiency are hard to estimate. A 2007 Wake Forest University of Medicine study found that in a sample of 976 adults 65 years of age or older, 75 percent of women and 51 percent of men had low vitamin D levels. Researchers at Oregon State estimate that 70 percent of Americans have less than optimal levels of vitamin D, and nearly a billion people worldwide are vitamin D deficient.
Vitamin D status is assessed by measuring how much is in the blood. A vitamin D blood level below 12 ng/mL is considered deficient. Vitamin D deficiency leads to rickets and many other health problems. A vitamin D value between 12 and 20 ng/mL is considered inadequate for bone and overall health.
Many experts consider a vitamin D value of 30 ng/mL to be the baseline for general health. The benefits of vitamin D are evident when values are optimized between 30—80 ng/ml.
Supplementing With Vitamin D
You can ask your doctor to order a vitamin D blood test to assess your values and determine supplementation needs. If you are healthy but low in D, 2,000 to 7,000 IUs of vitamin D per day should be sufficient to maintain year-round serum levels between 40-70 ng/mL. If you suffer from chronic illness (diabetes, cancer, multiple sclerosis), obesity, or gastrointestinal disorders (celiac or crohn’s disease), you may require larger doses to maintain vitamin D above 30 ng/ml.
To get your vitamin D from the sun, you need to get regular full-body sun exposure without the use of sunscreen. Caucasian skin produces 10,000 IUs of vitamin D from several hours of full-body sun exposure, however, if you have darker skin, vitamin D synthesis will be lower. In national surveys, African Americans have a lower vitamin D status than non-Hispanic whites and Mexican Americans. The most likely explanation for this disparity is that melanin, the primary determinant of skin pigmentation, functions as an optical filter of ultraviolet (UV) light, limiting vitamin D synthesis. Darker pigmented individuals require longer UV exposure times than lighter pigmented individuals to synthesize equivalent amounts of vitamin D.
Excellent Reasons To Take Vitamin D
1. Bone Health
Bone health is one of the best known reasons to take vitamin D. Low levels of vitamin D contribute to osteopenia, osteoporosis, and bone fractures. A 2010 study suggests that calcium and vitamin D supplementation is an essential component in maintaining bone health. Together these minerals can improve bone mineralization, and correct secondary hyperparathyroidism, thereby preventing falls.
2. Muscle Strength
Muscle is a target organ for vitamin D, which means that deficiencies lead to muscle weakness. Specifically, a lack of vitamin D impairs force production by weakening muscle contractions. There is also evidence that vitamin D helps you hold onto muscle mass, reducing the degradation of protein in muscle.
3. Muscle Power and Force Development
Optimal levels of vitamin D have been shown to improve muscle power and jump height. Researchers found that the ability of the muscles to contract and produce force is affected by vitamin D status. Participants in a 2008 study with low concentrations of vitamin D generated less power than those with higher concentrations, leading to the conclusion that vitamin D is significantly associated with power and force.
4. Lean Body Mass
Vitamin D is essential for the maintenance of muscle and for avoiding the development of fat in muscle. A 2010 study found that vitamin D shortage is associated with increased fat infiltration in muscle. Vitamin D deficiency was defined as a serum concentration less than 29 ng/ml, which 59 percent of the study subjects were below. The vitamin D-insufficient subjects had 24 percent more fat in their muscle than those with vitamin D levels above 29 ng/ml, leading researchers to conclude that vitamin D prevents fat gain.
5. Treatment of Psoriasis and Skin Disorders
Vitamin D affects skin inflammation making the treatment of disorders such as psoriasis a good reason to take vitamin D. Recent studies have shown that patients suffering from a variety of inflammatory conditions including psoriasis, dermatitis, dandruff, eczema, rosacea, and severe acne were vitamin D-deficient. Vitamin D may help retard the abnormal growth and shedding rate of skin cells in conditions like psoriasis.
6. Blood Sugar Regulation and Insulin Resistance
Protecting your metabolism is a smart reason to take vitamin D. Supplementing with vitamin D has been shown to increase insulin sensitivity, indicating that it may be an effective way to offset the symptoms of diabetes. A 2009 study of South Asian women with insulin resistance (in a pre-diabetes state) found that taking 4,000 IUs of vitamin D a day significantly improved insulin sensitivity.
7. Prevent Multiple Sclerosis
Vitamin D deficiency is known to contribute to bone mineral loss and osteoporosis, but the good news is that taking vitamin D has a protective effect on the risk of multiple sclerosis (MS). In the Nurses' Study, over 190,000 women who used supplemental vitamin D had a 40 percent lower risk of MS than women who did not supplement. Findings from a second study of African Americans with MS published in 2011 supported the link between vitamin D deficiency and MS.
8. Prevent Cancer
Vitamin D has been linked with fighting numerous cancers including lung, breast, colon, and prostate. In the case of lung cancer, supplementing with Vitamin D may help offset elevated levels of an enzyme that is associated with the development of aggressive lung cancer tumors. In a 2011 study, lung cancer patients with high vitamin D levels had an 81 percent survival rate after five years compared to those with low levels (41 percent survival rate). Scientists are investigating other anti-cancer reasons to take vitamin D.
9. Treat Asthma
Every cell in the body has a vitamin D receptor, including those in the lungs. One reason to take vitamin D is fewer asthma symptoms. A study at the University of Colorado-Denver found that supplementation of vitamin D in patients with asthma may result in decreasing asthma severity. This study also found that participants with lower vitamin D levels had more lung inflammation.
10. Male Reproductive Health
Vitamin D affects male reproductive health, improving the health of sperm. A study from Denmark found that men with vitamin D deficiency had a lower proportion of mobile, healthy sperm compared with men with high vitamin D levels. Surveys estimate 51 percent of men have low D levels, making supplementation a first line of defense for men who are struggling to conceive.
11. Cardiovascular Health
Vitamin D is protective of heart health, whereas deficiency is linked with cardiovascular disease. The Framingham Heart Study followed 1739 Caucasian individuals with a mean age of 59 years without prior cardiovascular disease. After 5 years, the study showed that those with clinically low vitamin D developed high blood pressure at greater rates and had a two-fold greater risk of cardiovascular incidence.
12. Brain Health
Vitamin D protects the brain and low levels are associated with brain and memory problems, specifically in individuals over age 75. A 2010 study of 752 women found that women with vitamin D deficiency had increased rates of significant cognitive impairment. Low levels of vitamin D have previously been associated with neurological disorders like Alzheimer's disease, but this new research indicates the importance of ample vitamin D for optimal brain health.
13. Fetal Brain Development
In light of the role of vitamin D for protecting the aging brain, it is not surprising that it plays a role in fetal brain development. Scientists have concluded that pregnant mothers who are deficient in vitamin D have fetuses with developmental impairment in brain cells. Additionally, there is evidence that the offspring of vitamin D-deficient mothers are more susceptible to schizophrenia, bone disorders such as rickets, and the development of diabetes.
14. Female Reproductive and Maternal Health
Vitamin D is important for female fertility and affects fetal implantation in the uterus. Additionally, vitamin D-deficient women are at risk for pre-eclampsia and gestational diabetes. Interestingly, due to the effect of vitamin D on muscle strength and function, women with low vitamin D levels appear to have a higher rate of cesarean sections due to sub-optimal muscle performance and strength during pregnancy.
15. Treat Depression and Brain Disorders
If you are vitamin D-deficient, your risk of depression increases significantly. Vitamin D enhances the metabolic processes in brain neurons, promoting antioxidant activities that protect brain cells from degeneration. Additionally, vitamin D promotes nerve growth and is an essential enzyme involved in the production of neurotransmitters that regulate mood. Preventing bipolar and schizophrenia are two more reasons to take vitamin D.
16. Immune Function
Vitamin D is crucial to activating immune defenses. Low vitamin D compromises the body’s T-cells ability to fight off serious infections. Specifically, dormant T-cells rely on vitamin D to activate them so that they can effectively battle harmful pathogens that enter the body. Along with helping immune cells fight viruses such as the flu and covid vitamin D helps increase the immune response by limiting inflammation, a major obstacle to healing and health.
17. Kidney Health
Vitamin D is important for kidney health, helping manage inflammation that harms the kidney. Vitamin D is a key compound in treating chronic kidney disease and decreasing subsequent death rates. Understandably, individuals who are vitamin D deficient are at risk to develop kidney disease.
18. Treat Hypertension and Metabolic Diseases
Vitamin D deficiency is strongly associated with high blood pressure and associated metabolic diseases such as diabetes and obesity. Vitamin D supplementation is most effective at significantly reducing blood pressure when it is paired with calcium.
19. Prevent Obesity
Low vitamin D levels are a risk factor for gaining fat. Research shows that body fat mass is higher in individuals with vitamin D deficiency and that this shortage correlates with elevated levels of parathyroid hormone and intracellular calcium, considered to be major factors in determining obesity. The increased calcium levels trigger metabolic pathways that promote the accumulation of fat tissue and suppress fat burning. Previously it was thought that low vitamin D levels were consequences of obesity but a 2010 study shows that reduced levels actually play a role in the development of obesity.
20. Prevent Parkinson’s Disease
Parkinson’s disease is an incurable disorder of the nervous system, with symptoms that include trembling hands, stiff muscles, digestive and urinary problems, and a decrease in dexterity and coordination. The average age of onset of the disease is 60, and when the disease appears before the age of 40 it is referred to as early-onset Parkinson’s disease. There is a relationship between low Vitamin D levels and the early onset of Parkinson’s disease. Research is still in the early stages but brain and nervous system health are two more reasons to take vitamin D.
21. Prevent Rickets and Osteomalacia
The development of rickets and osteomalacia is directly related to vitamin D deficiency. Rickets is a childhood disease that is characterized by the softening of bone, leading to bone fractures and skeletal deformities. For adults, osteomalacia is associated with osteoporosis but is a separate disease that starts with aches in the lumbar region and spreads to the arms and ribs. Bones become deformed, often fracturing, and sufferers typically complain of chronic fatigue. Getting your vitamin D level up to par is a first line of defense for bone health and quality of life.
22. Prevent and Treat Chronic Obstructive Pulmonary Disease
Chronic Obstructive Pulmonary Disease, also known as COPD, is characterized by respiratory weakness and the obstruction of the air pathways in the lungs. It typically manifests as emphysema and chronic bronchitis and can be treated by vitamin D supplementation. Considering the effect of vitamin D on increasing muscle strength and diminishing the symptoms of asthma, it is logical that it has positive effects on COPD. A 2011 study found that individuals supplementing with a monthly dose of 100,000 IU of vitamin D had significant improvements in all measures of COPD including oxygen consumption.
23. Treat Autoimmune Conditions
Vitamin D deficiency affects immune function and is associated with an increased risk of AIDS progression and death from the disease. Conversely, in recent studies individuals with the highest levels of vitamin D have been seen to have a significantly lower risk of death than those with low levels. Vitamin D deficiency is seen as an important co-factor in HIV progression and supplementing with the vitamin may be an effective anti-viral therapy.
24. Treat Childhood Anemia
Low vitamin D levels in children can cause anemia, a severe condition that leads to the damage of vital organs by depriving them of oxygen. Anemia occurs when the body has too few oxygen-carrying red blood cells and is diagnosed by measuring hemoglobin levels. Symptoms of mild anemia include fatigue, lightheadedness, and low energy. Getting vitamin D levels up should be part of overcoming anemia in kids.
25. Prevent Infections
Adequate vitamin D is crucial for the immune system and it may be used as a primary treatment for viral, bacterial, and fungal infections. In a recent review, researchers found that treatments of all of the following conditions benefit from optimal vitamin D: tuberculosis, psoriasis, eczema, Crohn's disease, chest infections, wound infections, influenza, urinary tract infections, eye infections, and wound healing.
Vitamin D is a wonderful nutrient that is essential for life. What we haven't covered in this article is how vitamin D works together with other nutrients do its work in the body. In fact, there are at least eight synergistic that work with vitamin D to keep you at peak mental and physical performance. That's eight more reasons to take vitamin D!